The invention relates to a memory device, and more particularly, to a phase change memory device and a method of forming the same.
Due to developments in the electronics industry, characteristics such as fast read/write operation speed, non-volatility, and low operating voltage are required. Recently, a phase change random access memory (PRAM) having a phase change layer has been proposed as an advanced memory device capable of satisfying such requirements.
Since the phase change layer can indicate at least two differentiable states, for example a crystalline state and an amorphous state, and at least one intermediate state therebetween, it may be used as a memory element. The amorphous state indicates a relatively higher specific resistance than the crystalline state, and at least one intermediate state indicates a specific resistance between the amorphous state and the crystalline state.